Papers by Keyword: UAV

Abstract: The use of Unmanned Aerial Vehicles (UAVs) is increasing as their usage enhance many activities in our modern world. These include their specific roles in warfare, surveillance, agricultural activities, entertainments with attendant economic importance. In areas grappling with insecurity challenges due to banditry, kidnappings, oil spillage and theft, farmers and herdsmen clashes, utilizing more than one UAV in an area for surveillance is not only good but more advantageous. If many UAVs are used in an area at the same time, they are termed swarm or group of UAVs. Their operations in this manner, are seen as more scalable and reliable mode of using UAVs in current and future applications. Thus, usage of multiple UAVs that operate together as a cohesive unit are redundant and scalable, performing tasks that would be challenging or inefficient for a single UAV to accomplish. However, operating a group of UAVs as one unit can become expensive and risky if they are not properly coordinated. The UAVs may collide, causing catastrophic damage and requiring costly repairs. The need for autonomous coordination therefore comes from the vast number of vehicles, which might be intrinsic members of the system as a whole. Also, all UAVs in the swarm are to contribute to the effective execution of task without wasting resources. These imply that an intelligent coordination algorithm that implements awareness for swarm UAVs to avoid risky states is required. This paper presents the development and implementation of an algorithm for intra-swarm collision avoidance by treating each UAV in a swarm unit as individual agent capable of a homogenous number of tasks modelled as contours using their field of view and received signal strength indication.

Abstract: Civil infrastructure is prone to deterioration due to several factors like loading and environmental agents. Condition assessment of these infrastructures is done on a visualization basis by the field inspector. The data collected by the inspector is biased and depends on the perception, experience, and visuals of the inspector. The data collected in terms of images and characteristics of the deterioration is recorded on a qualitative basis in the data log. The report is then presented to the managers or decision-makers to make decisions on the maintenance of the facility. In this era, various sensing and visualization technologies are available that can be utilized to create a digitized as-built model in 3D with exact dimensions and deteriorations, also known as a 3D re-constructed model. In this research, a 3D reconstructed model of an elevated overhead water tank has been created using laser scanning, UAV (Unmanned aerial vehicle). Artificial intelligence has been used to detect and measure cracks or openings on the surface of the structure. Deflection and rotation of the elements of the structure have been quantified by superimposing the point cloud model over the as-planned model in the interface of Navisworks.

Abstract: The evaluation and walk-around check before an aircraft flight are essential for ensuring aircraft safety. This paper describes a method for creating a system capable of detecting and identifying damages on aircraft surfaces using imagery captured from UAV-based aerial platforms, achieving real-time Internet of Things (IoT) monitoring via other devices. Our aim in this project is to detect skin damage, such as scratches, cracks, and dents, that pose significant threats to the structural integrity and safety of aircraft. Traditional inspection methods are often time-consuming and labor-intensive, making real-time detection systems essential for timely maintenance and safety assurance.The system utilizes UAVs to capture high-resolution aerial images of aircraft surfaces. These images undergo processing by trained machine learning algorithms to detect and classify desired objects in real time at the ground station. The results of the image processing can then be monitored via IoT devices. Experimental results demonstrate the system's effectiveness and efficiency in identifying skin damage on aircraft materials. However, certain limitations have emerged, including restricted coverage of defect types, reduced accuracy with increased class numbers, and substantial hardware requirements. Despite these shortcomings, the system remains promising for enhancing aircraft safety through proactive maintenance and defect detection.

Abstract: An ornithopter is a power-driven aircraft that utilizes a flapping mechanism. This paper summarized the research and development carried on Unmanned Aerial Vehicle (UAV) till date and reclaims the efficiency on ornithopter namely the flapping frequency, Reynold number, kinematics, transmission system and flapping mechanisms. The present investigation explores the design of a biologically inspired flying Unmanned Aerial Vehicle. For its execution, varied of analyses of flight mechanics, stability, and the control of flapping motion. The theoretical techniques involved in the construction of an ornithopter have investigation for surveillance, military application, spy work, and rescue operations. Additionally, the material used for construction of ornithopter is also discussed. The benefits of the flapping mechanism for are not limited. This paper also reviews the research and development done on the previous UAVs and from small birds to large birds. In this paper the experimental analysis has been done on the ANSYS Fluent on a semi elliptical wing design with a wingspan of 0.25m which delivered the output of how the wind flow and pressure can affect the efficiency of a flapping wing according to the varying angle of attack. This concluded the selection of a material with low stiffness.

Abstract: Helicopter Unmanned Aerial Vehicle (HUAV) is recently used in agriculture due to its dynamic, flexible, vertically take-off/landing, hover and to laterally fly. The HUAV was researched and designed with purpose of greatly reducing manpower, limited direct contact of human with toxic substances, reducing time working in parallel with improving quality and yield. This paper focused on the main rotor blades of HUAV with 15 kg useful load. The main rotor was first designed and then numerically validated by using computational fluid dynamic (CFD) tool in ANSYS software. The aerodynamics characteristics of main rotor blades of HUAV such as pressure, velocity, thrust, drag ...were carried out at hovering flight mode. Finally, strengthen analysis of main rotor blades were checked using computational solid dynamic (CSD) tool in ANSYS software. The aim of this paper was to check whether the designed blades of main rotor were durable enough or not to continue the next design steps.

Abstract: Mechanical properties of several composite materials were assessed in order to establish their suitability for unmanned aerial vehicle components manufacturing. The materials under evaluation consisted in E-glass fiber (satin/twill weave) impregnated with polyester, respective epoxy resin. The study was focused on two mechanical tests: low-velocity impact and tensile tests. Based on the results obtained, it was observed that configurations reinforced with twill weave presented higher tensile strength compared with satin reinforced configurations. Moreover, they presented a lower damage degree in case of impact tests. It was concluded that fabric quality has a considerable influence on the impregnation process and on the composite material mechanical properties. In the present case, the twill weave impregnated with epoxy resin can be used to manufacture small range UAV components.

Abstract: A gyro-stabilized antenna platform could implement a real-time motion compensation for a SAR system. Since motion errors reduce during the data acquisition process, post-processing load also reduces. Subsequently, production of well-focused, and high-resolution synthetic aperture radar (SAR) images is conceivable. The research is to design a gyro-stabilized SAR antenna platform that compensates motion in real time during data acquisition. This paper explains the study of undesired motion (error) for typical UAV SAR. The resulting angle ranges of yaw, pitch, and roll describe the magnitude of the motion errors. The design of a gimbal system as a stable antenna platform considers yaw, pitch and roll range parameters. IMU optimization (Complimentary Filter, and Madgwick Filter algorithms are tested and compared in order to decide the optimum optimization scheme for the antenna platform. The data fusion and gradient descent algorithm from Madgwick show significant performance. The implementation of the optimized IMU algorithm and control on a field programmable gate array (FPGA) has resulted in a very effective stable antenna platform.

Abstract: Due to the rapid scientific and technological developments in the aerospace industry, the requirement for safety and energy absorption efficiency is increasing, and in order to achieve that target, the analyzing of the sudden crash is required to know how to reduce it. Therefore, the main objective of the present work is to analyze the crashing response of the hybrid composite fuselage structure during different impact landing conditions. Moreover, extract the maximum acceleration at the most important locations in the UAV fuselage where most of the critical system is installed. The explicit non-linear finite element software LS-DYNA/WORKBENCH ANSYS is chosen to simulate the crushing of the referenced and the proposed UAV fuselage and investigate the maximum crushing accelerations responses on the payload under different landing conditions. The numerical results show that strengthen the fuselage structure using hybrid composite material has a notable effect on the energy absorption, and transferred acceleration on the payload. Moreover, the hybrid composite fuselage structure can reduce the transferred acceleration on the payload up to 39.65% in comparison with the metal fuselage. In addition, to study the crash analysis during sudden accidents is very important, in order to find the way to reduce it, but can’t avoid it. Hence, the UAV payload should be arranged to avoid the maximum acceleration.

Abstract: In the last several decades past, Helicopters UAVs (Unmanned Aerial Vehicles) have quickly developed and day by day, they play an important role in human life. As it is well-known, helicopters UAV make some outstanding characteristics such as light weight, flexibility and particularly automatically controlled. By applying these characteristics, we research and manufacture Helicopter UAV using for spraying pesticide in agriculture. One of the most important components is main rotor because main rotor generated thrust, drag and momentum. Helicopters UAV efficient changed depending on main rotor. The research works focus on aerodynamics characterization of main rotor in helicopter UAV. This work uses CFD tool in ANSYS CFX software to calculate the aerodynamics parameters generated by main rotor using in UAV. The aim is to characterize the aerodynamics characteristics such as thrust, drag, pressure, aerodynamics quality on the different flight modes (hover, vertical and forward flight). Firstly, the simulations are carried out in hover flight mode with different blade pitch angles. The results are compared to experiment date in another research to validate numerical results. Then, the simulations are carried out in vertical flight mode and forward flight mode. The results showed that thrust and drag coefficient creased with increasing blade pitch angle. When blade pitch angle started from 1800, thrust coefficient decreased but drag coefficient increased sharply. The rotor performance was measured by aerodynamics quality and numerical results showed that the best rotor performance was at 900. In the vertical flight mode, the thrust and drag coefficient decreased with increasing vertical velocity but rotor performance increased slightly. The best vertical velocity for vertical flight is around 2 m/s and 3 m/s. Finally, in forward flight mode, the aerodynamics characterizations of rotors depended on azimuthal angular position of blade or time. Our helicopter operates in environment with light gust. The results showed the change of aerodynamics coefficient to time. Both thrust and drag coefficient changed but the rotor performance did not change much.

Abstract: In this article review of chosen control algorithms used for small UAV at Department of Control Systems of Rzeszów University of Technology and their properties is presented. At first, control laws based on modified PID algorithms are described. The example of modification is the use of double differentiation in the algorithm. Proposed modifications improve control quality. Next, model following LQR algorithms is introduced. Implementation of that algorithm improves control quality in the flight at trajectory. In the algorithm presented integration between desired trajectory and plant trajectory is introduced as an additional state.Another algorithm which is presented is sliding mode control algorithm as an example of robust control. It allows you to control plane in event of a fault. Appropriate selection of sliding surface ensures the stability of the system and good quality control under normal operating conditions and enables flight in the event of non-critical damage. To improve the quality control in emergency mode, the parameters of the sliding surface during flight can be modified. The last presented algorithm is model reference adaptive controller. The adaptation mechanism is derived from second Lyapunov method. It also enables control in the case of chosen faults. An example presented in the article is realized for roll angle control. In the case of control surface fault (e.g. aileron or rudder), the algorithm enables aircraft control. In that case control surface fault is treated as an uncertainty of model used.